title: Impacts of highway traffic exhaust in alpine valleys on the respiratory health in adults: a cross-sectional study.
abstract: BACKGROUND
  Most studies having shown respiratory health effects from traffic exhaust were conducted in urban areas with a complex mixture of air pollution sources. This study has investigated the potential impact of traffic exhaust on respiratory symptoms among adults living along a Swiss alpine highway corridor, where traffic exhaust from the respective trans-Alpine highway is the predominate source of air pollution.
  
  
  METHODS
  In summer 2005, we recruited 1839 adults aged 15 to 70 from a random sample of 10 communities along the Swiss alpine highway corridors. Subjects answered a questionnaire on respiratory health (asthmatic and bronchitic symptoms), risk factors, and potential confounding variables. We used logistic regression models to assess associations between respiratory symptoms and traffic exposure being defined a) as living within 200 m of the highway, and b) as a bell-shaped function simulating the decrease of pollution levels with increasing distance to the highway.
  
  
  RESULTS
  Positive associations were found between living close to a highway and wheezing without cold (OR = 3.10, 95%-CI: 1.27-7.55) and chronic cough (OR = 2.88, 95%-CI: 1.17-7.05). The models using a bell-shaped function suggested that symptoms reached background levels after 400-500 m from the highway. The association with chronic cough was driven by a subgroup reporting hay fever or allergic rhinitis.
  
  
  CONCLUSIONS
  Highway traffic exhaust in alpine highway corridors, in the absence of other industrial sources, showed negative associations with the respiratory health of adults, higher than those previously found in urban areas.
authors.affiliation: Swiss Tropical and Public Health Institute, Department of Epidemiology and Public Health, Basel, Switzerland.
authors.forename: Marianne E
authors.initials: ME
authors.lastname: Hazenkamp-von Arx
authors.forename: Christian
authors.initials: C
authors.lastname: Schindler
authors.forename: Martina S
authors.initials: MS
authors.lastname: Ragettli
authors.forename: Nino
authors.initials: N
authors.lastname: Künzli
authors.forename: Charlotte
authors.initials: C
authors.lastname: Braun-Fahrländer
authors.forename: Lee-Jane S
authors.initials: LJ
authors.lastname: Liu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000397:Air Pollution / Q000009:adverse effects*; D003430:Cross-Sectional Studies; D004781:Environmental Exposure / Q000009:adverse effects*; D004784:Environmental Monitoring; D062665:Epidemiological Monitoring; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D015995:Prevalence; D012140:Respiratory Tract Diseases / Q000453:epidemiology* / Q000209:etiology; D012307:Risk Factors; D012423:Rural Health; D011795:Surveys and Questionnaires; D013557:Switzerland / Q000453:epidemiology; D001335:Vehicle Emissions
chemical_list: D001335:Vehicle Emissions